I developed the Quantile Normalization algorithm and showed that it performed well for microarray data. Working with several collaborators I created the RMA algorithm for producing expression measures for Affymetrix GeneChip data. A great deal of my research has focused on the development and application of Probe Level Models (PLM) for the analysis of high-density oligonucleotide array data. One interesting application of PLM is for the quality assessment of GeneChip data. The PLM Image Gallery contains a number of images demonstrating the results of these techniques.

In 2005 I spent time at Predicant Biosciences developing statistical and computational techinques for the analysis of mass spectrometry data.